The present invention relates to DC-52 derivatives.
DC-52 derivatives have an antitumor activity and are useful as antitumor agent.
JP-A-170189/1982 discloses DC-52, which is a compound represented by the formula: ##STR2## and exhibits an antitumor activity against lymphocytic leukemia P388, etc. in addition to an antibacterial activity against various bacteria.
U.S. Pat. No. 4,650,869 (JP-A-210086/1984) discloses DX-52-1, a derivative of DC-52, having an antitumor activity and represented by the formula: ##STR3## EP-A-283521 (JP-A-88183/1988) discloses a derivative represented by the formula: ##STR4## wherein X represents chlorine, bromine, iodine, hydroxyl, formyl, hydroxyiminomethyl, cyano, nitro, amino or lower alkanoylamino, Y represents hydroxyl and Z represents cyano, or Y and Z are combined together to represent --O-- as --Y--Z--. JP-A-183583/88 discloses a derivative represented by the formula: ##STR5## wherein R represents hydrogen, alkanoyloxy having 1 to 18 carbon atoms, oleoyloxy, linoloyloxy, linolenoyloxy, retinoyloxy, unsubstitued or substitued benzoyloxy in which the substituent is halogen or lower alkoxy, mercapto, alkanoylthio having 1 to 18 carbon atoms, oleoylthio, linoloylthio, linolenoylthio, retinoylthio, unsubstituted or substituted benzoylthio in which the substituent is halogen or lower alkoxy, azido, amino, --NHZ [in which Z is an .alpha.-amino acid residue (wherein the OH of carboxyl of the .alpha.-amino acid is removed and the amino and/or carboxyl when it is present may be protected by their protective groups conventionally used in the peptide synthetic chemistry), pyruvoyl, citroyl or acetyl], cyano or halogen, and X represents cyano or hydroxyl. EP-A-262984 discloses a compound represented by the formula: ##STR6## wherein each of R.sup.1 and R.sup.2 independently represents hydrogen, lower alkoxy, azido, amino, lower alkylamino, dilower alkylamino, cyclic amino, lower alkylthio, or unsubstituted or substituted arylthio, X represents hydroxyl and Y represents cyano, or X and Y are combined together to represent --0-- as --X--Y--.